Liquid seal gas cut-off valves



NOV- 10, 1964 H. G. STALLKAMP ETAI. 3,155,254

LIQUID SEAL GAS CUT-oFF vALvEs Filed May 10, 1961 INVENTOR. Huber? G.Siallkamp Edwin Durham AT T O RNEY United States Patent() 3,156,254LIQUID SEAL GAS CUT-OFF VALVES Hubert G. Stallkamp, Akron, and EdwinDurham., Wadsworth, Ohio, assignors to The Babcock & Wilcox Company, NewYork, NX., a corporation of New Jersey Filed May 10, 1961, Ser. No.109,073 3 Ciaims. (Cl. 137-253) The present invention relates topositive closing valves of the liquid sealing type, and moreparticularly to valves for selectively directing a hot gas streamcontaining a toxic material through alternative ow paths.

The invention is directed to an improvement in the construction andoperation of water sealing valves where a hot gas containingcombustibles, such as, for example, carbon-monoxide, may be burned forheat recovery purposes and to consume the combustible materials therein.Such hot gases may be obtained from a catalyst regenerative kiln wherethe gases may be at a temperature of the order of 1,000 F., a pressureof one pound gage and contains carbon-monoxide. When such gases areburned in a furnace in conjunction with a high heat value fuel, andpassed over heat recovery surfaces such as Vapor generating surfaces, itis absolutely essential that the gas flow be prohibited from enteringthe furnace whenever access to the furnace orthe heat exchange surfacesbecomes necessary. In installations of this type which involve acontinuously operating process, the shut-down of the furnace or vaporgenerator for maintenance and repair necessitates that the hot gasesfrom the regenerator kiln must be diverted from the heat exchangeapparatus and pass directly to the stack. The valve to accomplish thismust be completely effective so there will be no leakage ofcarbon-monoxide containing gas to the unit since inhalation of suchgases could be fatal to the operators during maintenance work within theheat recovery apparatus.

In accordance with the present invention, a pair of tanks are positionedin spaced side-by-side relationship with a common inlet connection forthe introduction of the hot gases thereto. Each tank is provided with anelongated duct which extends through the top of the tank vto a positionspaced above the bottom of the tank. The duct in each tank provides adischarge means for the movement of the gases through the 4tank enteringthe tank at its upper portion and discharging into an annular spaceformed between the walls ofthe tank and 'the discharge duct, firstflowing downward in the annular space and then upward to dischargethrough the duct. When it is desired to prevent the ow of gas throughone of the tanks, water is introduced into the tank, submerging thelower end of its discharge duct and thereby providing an effectivevalved seal against iow of gases through the particular tank.

Since either one or the other of the tanks will always be serving as acut-oif valve during operation, it is necessary to arrange the tankswith provision for adding makeup water to compensate for waterevaporated by the hot gases, otherwise the effectiveness of the waterseal will be impaired and the seal useless. Mere compensation forevaporation surprisingly has been found inadequate to overcome acorrosive water condition arising from the absorption of contaminantsfrom the gases. Gas eddy currents set up in the seal tank apparentlyhave been responsible for the creation of this condition. The rate ofmakeup flow therefore should be such as to provide both for evaporationat the gas-water level interface as well as for continuous overflow ofseal water.

In the present invention, this is accomplished by the use of an externalstandpipe on each tank, the lower end of which is connected to the tankat a point below the open end of the gas discharge duct. The upper endof the Patented Nov. 10, 1964i standpipe on each valve is connected witha horizontally disposed pipe that interconnects the upper end portionsof the standpipes of both valves. The connecting pipe is positioned at alevel above the lower end of the gas outlet duct so as to provide asufficient volume of water in 1 the itank to effect the necessary seal.The connecting pipe is provided with a common depending overflow pipewhich extends downwardly into a liquid seal. Advantageously, thestandpipes on each of the valves is provided with a gage glass whichgives an indication of the liquid level in each tank and can be used asan indicator for regulating the rate of iiow to or from the tank.

The various features of novelty which characterize our invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,its operating advantages and specific objects attained by its use,reference should be had to the accompanying drawings and descriptivematter in which we have illustrated and described a preferred embodimentof the invention.

Of the drawing:

ln the single figure a pair of water sealing valves is providedincluding the overiiow and sealing arrangement of the present invention.

In, the illustrated embodiment of the invention, a pair of horizontallyspaced closed tanks is provided to form a pair of sealing valves fordirecting the iiow of hot carbonmonoxide containing waste gases from anexterior source such as a catalyst regenerator kiin. lt will beunderstood that the valve of the type here described may be utilized forcontrolling the direction of flow of any gas through preferred iiowpaths, and that the hot gases, with or without toxic contaminants, maybe obtained from a source other than that indicated.

As shown in the drawing, the gases are delivered through a duct 1d whichdischarges into a horizontally disposed duct 11 opening at its oppositeends to the valves 13 and 14. Each valve, defined by upright cylindricalwalls 15 and 16 respectively, forming a tank-like container, is providedwith outlet ducts 17 and 18, respectively. Each outlet ductis coaxialwith respect to its respective valve 13, 14 and has an outside diameterless than that of the walls 15 and 16. Each duct 17 or 18 extendsdownwardly through a major portion of its respective valve 13 or 14 to aposition spaced above the bottom closure plate 2() or 21, respectively.As shown, each of the gas outlet ducts 17 and 18 is provided with aserrated lower end 22 and 23 respectively and additionally is providedwith a reinforcing wear saddle 24 and 25, respectively, mounted on theexterior wall thereof diametrically opposite the inlet from the duct 11.Advantageously, each of the outlet ducts 17 and 18 is provided with aninternal centering brace 26 and 27 for proper alignment of the duct withrespect to `the surrounding walls 15 and 16, respectively. The outletduct from each of the `tanks is provided with an extension, one of whichwill be connected with a furnace while the other is connected to a stack(neither shown) as required.

In the apparatus so far described, it will be noted the hot gasespassing through the duct 11i from, for example, a catalyst regeneratorkiln, may be passed through the duct 11 into either valve 13 or valve 14depending upon the level or height of the water seal in the valves 13 or14. In the embodiment shown, the Valve 13 is filled with suiicient waterto cut-off dow of hot gases from the duct 1i) through the discharge duct17. However, the valve 14 is open so that the gases will move from theduct 10 through the valve 14 and into the discharge duct 13. As hashereinbefore been suggested, one useful application for the presentinvention is in connection with the recovery of the sensible heat andthe combustible heat values contained in the gases discharged from acatalyst regenerator kiln. Under such circumstances, the duct 13 wouldbe connected with a furnace for the combustion of the CO containinggases. The gases discharged from such a furnace, containing bothcombustible and sensible heat values would thereafter be passed overheat exchange surfaces for the generation of steam, for example. Afurnace with heat exchange apparatus of the type described isillustrated in U.S. Patent 2,840,049.

When operated for the purposes described, the valve arrangement withvalve 13 closed and valve 14 opened, such as illustrated in the drawing,could be maintained in this relationship for weeks at a time. Underthese circumstances, eddy currents of hot gases would circulate in theannulus within the valve 13 and would tend to evaporate the watermaintaining the seal therein. Moreover, the contact between the gasesand the water at their interface would tend to cause condensation ofcorrosive materials from the gas and its absorption into the water. Thetendency therefore would be to create a corrosive condition in the waterin the lower portion of the valve 13 to the detriment of the metallicwalls 1S. It will, of course, be understood that evaporation of thesealing water cannot be tolerated since the water level in the valve 13must be maintained substantially uniform to provide the sealing effectof the valve. In the present invention, means are provided formaintaining the requisite water level in the valve and at the same timefor replenishing the sealing water at a rate which will avoid thecreation of corrosive conditions in the valve.

As shown in the drawing, water is supplied to the lower portion of thevalve 13 through a valved inlet pipe 30 which is arranged with suticientcross-sectional ow area to permit rapid lling of the valve when it isintended to be used to cut-ott` oW of gases therethrough. For dischargeof water from the valve, the pipe 31 connecting pipe 30 and the valve isconnected with a discharge pipe 32 of crossasectional ow dimensions topermit rapid discharge of water. Pipe 32 is likewise provided with agate valve or the equivalent so that ow of water therethrough may beregulated for discharge to a sump 34.

The valve 14 is similarly provided with an inlet valved pipe 35, pipe 36and discharge line 37. The discharge from valve 14 through pipe 37 is toa sump 33 which may be connected to a common water disposal pit or sewersuch as indicated on the drawing.

The valved water inlet pipes 39 and 35 are intended to have a suicientflow volume to submerge the serrated edges 22 and 23 of the dischargeducts 17 and 18, respectively, at a high rate so as to quickly andpositively actuate either valve. The serrated edges on the dischargeducts 17 and 1S are intended to reduce water carryover through thedischarge ducts during the lling of the valves 13 and 14.

The valve 13 is additionally provided with a relatively small diametermake-up water ow pipe 4h, with the flow therethrough regulated by thevalve 41 for the continuous ilow of make-up Water into the valve 13, andwith the capacity of this line somewhat in excess of the evaporatingrate of water from the closed valve 13. The valve 14 is similarlyprovided with a make-up water pipe 42 and a valve 43 for regulation ofmake-up water ilow to the valve 14 when such is required.

The ilow of make-up water to each of the valves 13 and 14, when in usefor gas cut-oit purposes, necessitates the provision of an overow pipeto dispose of the excess water. As shown, the overflow pipe arrangementconsists of a horizontally disposed section of pipe 44 connected with aT tting 45. The pipe 44 is located intermediate the bottom plate 20 andthe serrated edge 22 of the out.et duct 17. The T connection 45 isprovided with a plug 46 opposite the pipe 44 connection and anupstanding pipe section or standpipe 47. The upper end of the standpipe47 is likewise provided with a T fitting il?) with the side outlettherefrom opening to a generally horizontally disposed pipe section Stiwhich is connected with a T fitting 51 intermediate the horizontalspacing between the valves 13 and 14.

The upper end of the T lititng 48 is provided with a reducer and aninverted U-shaped connection to a gage glass 49. The gage glass 52 isconnected at its lower end to the pipe 47 upwardly adjacent the Tfitting 45. With the arrangement described, the gage glass 49 will givea true indication of the water level in the valve 13. Moreover, due toits location and connection with the standpipe 47, the gage glass willtend to remain clean for easy reading.

The valve 14 is similarly provided with pipe 52, a T fitting 53,standpipe 54, upper T fitting 55 and a generally horizontally disposedpipe 56 connected to the T iitting 51 opposite the pipe Sti of valve 13.It is also of advantage to provide a gage glass 57 for the standpipe S4where the gage glass is connected to opposite end portions ot thestandpipe as described in connection with the gage glass for valve 13.The T iitting 51 is also provided with a depending pipe 58 which has itslower end submerged in a water seal 60.

In the operation of the overtlow system described, the make-up waterintroduced through the pipe 4t) in connection 31, for example, maintainsthe level of sealing water in the valve 13. Excess water will passthrough the standpipe 47 and pipe 5t) for discharge through thedepending pipe 58. Any gases or non-condensible vapors entrained withthe water passing through the pipe 50 will discharge into the valve 14by way of the ow path including pipe 56 and standpipe 54. Thus, any suchgases or vapors vented from the valve 13 through the overflow systemwill not be discharged to the atmosphere but will mingle with the gasespassing through the valve 14 toward the furnace (not shown).

While in accordance with the provisions of the statutes we haveillustrated and described herein the best form and mode of operation ofthe invention now known to us, those skilled in the art will understandthat changes may be made in the form of the apparatus disclosed withoutdeparting from the spirit of the invention covered by our claims, andthat certain features of our invention may sometimes be used toadvantage without a corresponding use of other features.

What is claimed is:

1. Water sealing valve apparatus for the selective tlow of hot gasesfrom a common source to points of use comprising walls forming a pair ofspaced upwardly elongated tanks each having a gas discharge duct with alower open end spaced above the bottom of the tank, a gas inlet openinginto the upper portion of each tank, means for directing tiow of gasesto both of said inlet openings from a common duct, means includingvalved pipes for separately charging water directly to each of saidtanks to submerge the lower open end of each of the respective gasdischarge ducts and to thereby stop llow of gases therethrough, meansfor discharging water from each of Said tanks for flow of gastherethrough, and means for maintaining a continuous iow of waterthrough one of said valved pipes for overtiow of water from said tankonly when water is in said tank for gas tiow sealing purposes.

2. Water sealing valve apparatus for the selective ow of hot gases froma common source to points of use comprising walls forming a pair ofspaced upwardly elongated tanks each having a gas discharge duct with alower open end spaced above the bottom of the tank, a gas inlet openinginto the upper portion of each tank, means for directing low of gases toboth of said inlet openings from a common duct, means including valvedpipes for separately charging water directly to each of said tanks toselectively submerge the lower open end of each of the respective gasdischarge ducts and to thereby stop flow of gases therethrough, meansfor maintaining a substantially uniform level of sealing water in saidtanks including an overflow pipe means common to both of said tankshaving a common water sealed overow water discharge pipe, means fordischarging water from one of said tanks for 3. Water sealing valveapparatus for the selective flow of hot gases from a common source topoints of use comprising walls forming a pair of spaced upwardlyelongated tanks each having a gas discharge duct with a lower open endspaced above the bottom of the tank, a gas inlet opening into the upperportion of each tank, means for directing iow of gases to both of saidinlet openings from a common duct, means including Valved pipes forseparately charging Water directly to each of said tanks to selectivelysubmerge the lower open end of each of the respective gas dischargeducts and to thereby stop flow of gases therethrough, means fordischarging water from the other of said tanks for flow of gastherethrough, and means for maintaining a continually replenished bodyof water in a tank when the tank is provided with a gas sealing body ofwater including a standpipe positioned adjacent the lower portion ofeach of said tanks, a pipe opening from the lower end of cach of saidstandpipes to the lower portion of each of said tanks below the normalsealing water level therein, a pipe interconnecting the upper ends ofsaid standpipes above the normal sealing water level within said valves,an overow pipe extending downwardly from and opening in saidinterconnecting pipe and having its lower end submerged in a liquidseal, and means for continuously adding water directly to said tankcontaining sealing water to maintain overow through said standpipe withthe excess Water discharging through said overow pipe and simultaneouslyventing entrained gases through the other standpipe into said othertank.

References Cited in the le of this patent UNITED STATES PATENTS927,79-"r Harvey July 13, 1909 1,609,525 Moldenhaver Dec. 7, 19262,149,393 Foresman Mar. 7, 1939 2,199,728 Overson May 7, 1940 2,891,607Webster June 23, 1959

1. WATER SEALING VALVE APPARATUS FOR THE SELECTIVE FLOW OF HOT GASES FROM A COMMON SOURCE TO POINTS OF USE COMPRISING WALLS FORMING A PAIR OF SPACED UPWARDLY ELONGATED TANKS EACH HAVING A GAS DISCHARGE DUCT WITH A LOWER OPEN END SPACED ABOVE THE BOTTOM OF THE TANK, A GAS INLET OPENING INTO THE UPPER PORTION OF EACH TANK, MEANS FOR DIRECTING FLOW OF GASES TO BOTH OF SAID INLET OPENINGS FROM A COMMON DUCT, MEANS INCLUDING VALVED PIPES FOR SEPARATELY CHARGING WATER DIRECTLY TO EACH OF SAID TANKS TO SUBMERGE THE LOWER OPEN END OF EACH OF THE RESPECTIVE GAS DISCHARGE DUCTS AND TO THEREBY STOP FLOW OF GASES THERETHROUGH, MEANS FOR DISCHARGING WATER FROM EACH OF SAID TANKS FOR FLOW OF GAS THERETHROUGH, AND MEANS FOR MAINTAINING A CONTINUOUS FLOW OF WATER THROUGH ONE OF SAID VALVE PIPES FOR OVERFLOW OF WATER FROM SAID TANK ONLY WHEN WATER IS IN SAID TANK FOR GAS FLOW SEALING PURPOSES. 